1. Field of the Invention
This invention is generally directed to processes and devices utilized for coating products and especially sugar coatings to products including food, confectionery and pharmaceutical products and more specifically to adjustable double piston metering pumps which are used to supply a coating solution to rotating pans in which a product is retained and wherein the coating solution is supplied by the pumps on a predetermined schedule.
2. Brief Description Of The Related Art
The process and apparatus of the present invention may be utilized in substantially any coating of a food, confectionery or pharmaceutical product, however, the invention has been specifically developed for use in sugar panning processes wherein the product to be coated is contained in a revolving cylinder, referenced in the industry as a "pan". In sugar panning, numerous thinly applied layers of solution consisting of mixtures of sugar, water, corn syrup, various gums and coloring agents are applied to the product. Each layer or dosage of the coating solution is measured, applied to the product and allowed to "distribute" within the product before the product is dried using either hot or cold air, depending whether the coating process is a "Hot Process" or a "Cold Process". The number of layers or dosages applied is predetermined and the processes of coating continues successively until the predetermined number of coatings are applied to the product.
The process of applying liquid solution, allowing distribution time and subsequent drying is repeated numerous times until a desired appearance or size of the finished product is obtained. This may require from twenty to several hundred applications of the coating solution depending upon the particular product and the original intent for the panning of the product. Typically, confectionery items are coated with a crunchy candy shell which is usually colored, chocolate confections are coated to prevent melting and pharmaceutical products are made more palatable for consumer consumption.
Substantially all sugar panning is done in one of two types of equipment, conventional pans or automated pans. Automated pans are generally used by companies which specialize in panning in large mass utilizing batch processes of products in the one thousand to three thousand pound range. The pans are extremely large and the dosing functions are generally computerized such that the introduction of solutions, drying times and the like are automated. Automated pans are inherently more expensive than conventional pans and can easily cost in the hundreds of thousands of dollars.
Conventional pans are smaller and less expensive and process batch sizes from several pounds for laboratory uses up to several hundred pounds for commercial production models. The relatively small batch yield and inexpensive cost of conventional pans normally require that manufactures utilize a plurality of pans in series to accomplish coating tasks. Conventional pans are advantageous for processing multiple batches in various flavors and colors simultaneously.
Conventional pans are currently not automated for sugar panning. Dosing and control of drying air is done manually. Typically an operator proceeds from one pan to the next so as to control both the dosing and air supply to each pan in sequence. At each pan where the air is turned of, the coating solution is measured and poured into the revolving pan. The solution is allowed to distribute with the material to be coated before drying air is supplied. This process is repeated at each pan until the desired number of coatings is obtained. Unfortunately, extreme care must be taken so that the coating solution supplied to each pan is supplied not only in equal amounts but so that the amount of distribution time that the coating solution has with the product and the amount of drying time remains equal for all pans in a series of pans in order to provide a uniform product. A typical skillful operator may operate as many as fifteen pans in sequence.
In view of the foregoing, in the use of conventional sugar panning equipment, there is no method or apparatus for insuring uniformity of the coatings applied to products from one pan to the next and a great deal of reliance is placed upon the effective skills of an operator.